According to this theorem, the work done by all the forces (conservative or non-conservative, external or internal) acting on a particle or an object is equal to the change in kinetic energy of it. Let , ... be the individual forces acting on a particle. The resultant force is and the work done by the resultant force is: where is the work done on the particle by and so on. Thus, work energy theorem can also be written as: Work done by the resultant force is equal to the sum of the work done by the individual forces. There are a few points worth noting: